Stencil-character-forming apparatus



I H. P. ELLIOTT STENCIL-CHARACTER-FORMING APPARATUS I June 3, 1958 Filed Jan. 24, 1957 5 Sheets-Sheet 1 INVENTOR.

1747mm P1711035 I B A T lvl llllll June 3, 1958 H. P. ELLIOTT STENCIL-CHARACTER-FORMING APPARATUS 5 Sheets-Sheet 2 Filed Jan. 24, 1957 INVENTOR. fikrmm fill/502i BY a; 44%.,

June 3, 1958 H. P. ELLIOTT 2,837,196

STENCIL-CHARACTER-FORMING APPARATUS Filed Jan. 24, 1957 t 5 Sheets-Sheet 3 June 3, 1958 H. P. ELLIOTT 2,837,196

' STENCIL-CHARACTER-FORMING APPARATUS I Filed Jan. 24, 195'! 5 Sheets-Sheet 4 m7 yawn H.- P. ELLIOTT 2,837,196

STENCIL-=CHARACTER-FORMING APPARATUS 5 Sheets-Sheet 5 INVENTOR. 1922712022 1370067.

RN, a an June 3, 1958 Filed Jan. 24, 1957 United States Patent STENClL-CHARACTER-FORMING APPARATUS Harmon P. Elliott, Watertown, Mass.

Application January 24, 1957, Serial No. 635,990

11 Claims. (Cl. 197130) This invention relates to improvements in stencil-character-forming apparatus and more particularly to such apparatus wherein a platen roll and the keys of an electric typewriter coact to form characters on stencils in response to finger actuation of the keys in the conventional type-writing manner. The invention provides means whereby stencils are advanced intermittently along a track in response to actuation of a particular keyof the typewriter, and each stencil advanced to a particular station is automatically extracted from the track and moved into operative relation to the platen and keyactuated type characters in response to the same actuation of the particular key which caused its advance to said particular station. After suitable characters have been formed on the stencil in accordance with conventional typewriting procedures, actuation of the same particular key effects return of the extracted stencil to the track, advance of the stencils along the track, and extraction of the next succeeding stencil from said particular station'and movement thereof into operative relation to the platen and key-actuated type characters.

Heretofore, it has been customary procedure to form automatically advanced, and the next succeeding stencil at said transfer station is rapidly transferred from the track to said platen roll.

A further object of the invention is to provide a stencilcharacter-forming apparatus wherein depression of a control key conditions an electrical circuit for effecting a movement of a stencil in one direction followed in rapid succession by an advance of a succession of stencils, including said moved stencil, transversely of the movement of the first mentioned stencil, and movement of a next succeeding stencil of the succession in direction opposite to the direction of movement of the said first mentioned stencil.

Still another object of the invention is to provide stencil-character-forming apparatus wherein stencils, in succession, are advanced intermittently to a typewriter and each stencil along its course to the typewriter has its tissue portion first moistened and then blotted to condition it for receiving characters thereon when struck by type characters of the typewriter.

It is, moreover, my purpoe' and object generally to improve the structure and operative efficiency of stencilcharacter-forming mechanisms and devices, and more especially such mechanisms and devices which employ characters on stencils by actuating typewriter keys in a conventional manner following manual insertion of a stencil into coacting relation with the platen and the keyactuated type characters of the typewriter, or by manually inserting a stencil into a holder which is operable to bring the stencil into and out of coacting relation to the platen and type characters. The operator must manually insert and remove each stencil from the character-forming apparatus.

It is among the objects of the present invention to greatly increase the rate of production of character bear- Another object of the invention is to provide stencil-,

character-forming apparatus wherein stencils are advanced along a track in intermittent succession to a particular station in response to actuation of a predetermined key of an electric typewriter and wherein, subsequent to a said advance, the stencil advanced to said particular station is rapidly carried out of the track and. into coacting relation to the platen and type characters of the typewriter.

Yet another object of the invention is to provide a stencil-chairacter-forming apparatus wherein each stencil of a succession of stencils advancing intermittently along a track toward the platen roll of a typewriter is rapidly an electric typewriter, or the like.

In the accompanying drawings:

Fig. 1 is a front elevation of stencil-character-forming apparatus embodying features of the present invention;

Fig. 2 is an end elevation of the right hand end of the apparatus of Fig. 1; Fig. 3 is a top plan view of the apparatus of Fig. 1;

Fig. 4 is a cross-sectional view on line 4-4 of Fig. 1, on a larger scale; 1 r

Fig. 5 is a rear elevation at the stencil transfer station,

with portions of the typewriter omitted and showing thetransfer carriage in its lower position;

Fig. 6 is a view generally similar to Fig. 5 but showing the transfer carriage in its upper position; v Fig. 7 is a cross-sectional view on line 7--7 of Fig. 1;

Fig. 8 is a fragmentary top plan view of the moistenerblotter opening means;

Fig. 9 is a fragmentary cross-sectional view on line 9--9.of Fig. 8; l I Fig. 10 is a top plan view on line 1010 of Fig. 1; Fig. 11 is a simplified wiring diagram of the electrical circuit;

Fig. 12 is a fragmentary detail view, in cross-section on line 12-12 of Fig. 1; and

Fig. 13 shows a modified form of mechanism for direct drive connectionbetween the drive shafts which actuate the transfer carriage and the stencil advancing means.

Referring to the drawings, a typewriter is indicated generally at 10supported on a table top 12 which, in turn is supported on legs 14. The typewriter has a con ventional key-board 16, of which one key, hereinshown as key S, is connected for closing an electric switch 18, mounted below the key, when the key S is depressed, for a purpose which later will appear herein. r

The conventional carriage 20 of the typewriter operates generally in the customary manner. However, a relatively short platen roll 22 is substituted for the longer conventional platen roll, and the roll 22 is fixed on a substituted relatively long shaft 24 which extends a substantial distance beyond the right-hand end of the carriage and which is slidably and rotatably mounted in the spaced bearing portions 26', 26" of the bearing sup port 26 which extends upwardly from the table top 12.

A pinion gear 28 is mounted on the shaft 24 between whereby the shaft is rotated in response to rotation of the gear 28. A relatively long key way or spline 30 in the shaft permits axial movements of the shaft while gear 28 remains rotatably stationary between the bearing portions 26', 26". A gear segment 32 is pivotally mounted at 34 between the spaced upwardly extending parts of the bearing portions 26, 26", and the teeth of the segment are in mesh with the teeth of pinnion gear 28.

Below its-pivot 34, the segment 32 has a depending actuating arm 36 whose lower end has pin-in slot connection at 38 to the slotted portion 40 of a connecting rod 40 which extends forward and has it forward end pivotally connected at 42 to an arm 44 on shaft 46. Suitable bearings 48, 48 support the shaft 46. Another shaft 50 is suitably supported in bearings 52, 52, at right angles to shaft 46, and has driving bevelled gear connection to shaft 46 at 54. The inner end of shaft 50 has a sprocket 56 thereon with chain drive connection at 58, through the table top 12, to a sprocket 60 which is rotatable on one end of a power-take-oif shaft 62. Shaft 62 extends through a transmission casing 64 on a shelf 66 below the table top 12, and an electric motor 68 also is supported on shelf 66 with its shaft entering transmission casing 64 for driving shaft 62 counterclockwise as viewed in Fig. l. The other end of shaft 62 has a sprocket 70 rotatably mounted thereon with chain connection at 72 to a sprocket 74 fixed on cam shaft 76 above table top 12, this cam shaft 76 being mounted in suitable bearings 78, 78, and having an eccentric cam 80 fixed on its forward end.

Stencil tracks 82, 84 extend in spaced parallelism above the typewriter, being suitably supported on brackets86 extending upwardly from table top 12. The lower edge of upper track 82 is grooved at 83 and the upper edge of lower track 84 is grooved at 85, whereby opposite side edge margins of stencils 88 may be slidably engaged in the track grooves in a well known manner.

A supply of stencils is shown within the container 90 (Figs. 2, 3) which is mounted at the righthand end of the tracks 82, 84in Fig. l, the container extending rearwardfrom the tracks with its bottom wall 81 inclined a little downwardly toward the tracks. Whaving rollers 92 thereon constantly urges the stencils down the incline toward the tracks, and the rear wall of each track groove is cut away in a conventional manner so that the leading stencil of the supply in container 90 is urged toward engagement with the forward walls of the track grooves in position to be pushed along the tracks to the left in Fig. 1. The tracks are inclined. from vertical to stand generally perpendicular to the inclined bottom wall 91. A pusher member 92 is slidably mounted on the tracks and has a part 23 for engaging'back of the'right-h'and edge of the leading stencil of the supply when that stencil is in position to be pushed to the left along thetracks. A pusher lever 94 is pivotally mounted at 96 on standard 98 and has its upper end connected to pusher member92 bymeans of a pin-in-slot connection at 100, where a knob is shown to facilitate manual actuations of the pusher when the occasion arises.

The lever 94, below its pivot, is equipped with a roller 102 for engaging the periphery of the previously mentioned eccentric cam 88 on cam shaft 76. A relatively long coil spring 184 is connected at 106 to the lower end of lever 94 constantly biasing the roller 182 into engagement with cam 88. Hence, a complete rotation of cam shaft 76 effects a stencil-pushing actuation of lever 94 for advancing stencils in tracks 82, 84 one stencil-length to the left in Fig. l, and the lever and pusher member 92 are returned to their original positions following each stencil advance.

The stencil tracks 82, 84 extend to the left beyond the typewriter and deliver the stencils into a receiving container 108 which is generally similar to the supply container 90.

A weight According to the invention, however, stencils are rapidly transferred between the tracks 82, 84 and the platen roll 22 at a transfer station indicated generally at 110. In response to depression of typewriter key S, a stencil is advanced to station 119, and is rapidly transferred from the tracks to the platen roll 22 where printing characters may be formed on the stencil by the type characters of the typewriter by operating the typewriter in the conventional manner with the ribbon disabled. Also, ribbon typing on the frame of the stencil may be accomplished when desired. After a stencil has had desired characters impressed thereon, another depression of key S rapidly restores the stencil to its vacated place in the tracks, advances the stencils to bring a next succeeding stencil to station 118, and transfers this latter stencil from the tracks to platen roll 22.

Platen roll shaft 24 has fixed thereon two gear wheels 112, 114 spaced from opposite ends of the roll 22. The tracks 82, 84, at station 118, are so formed that the stencil advanced to station 11!? moves into a carriage frame indicated generally at 116 and having generally straight gear .racks 118, 120 in mesh respectively with the gear wheels 112, 114. Two plate elements 122, 124 are mounted in fixed spaced parallelism on the typewriter carriage, and the forward inner edge margin of each of these plates is grooved at 126 for slidable reception of the side edges of the carriage frame 116, outward of the gear racks 118, 120. Although the tracks 82, 84 have portions which extend continuously across the station 110, their groove walls are cut away and an advancing stencil moves into frame 116 while the latter momentarily is in its upper position, and the advanced stencil is promptly carried on the frame down to platen roll 22. While momentarily in its upper position, the stencil moved upward on the frame 116 is advanced to the left, in Fig. l, by the stencil coming into station 110.

Upward and downward movements of the stencilcarrying transfer frame 116 are in response to rotations of platen roll shaft 24 through the medium of the previously mentioned pinion gear 28 and gear segment 32. When key S is depressed, segment 32 moves counterclockwise about its pivot 34 (Fig. 2) to elevate transfer frame 116 and, following an advance of the stencils along the tracks 82, 84, moves clockwise back to its Fig. 2 position, thereby lowering the stencil which was advanced to station 110 into coacting relation with platen roll 22. Transfer frame 116 has track portions 128, 130 which, with the adjacent regular track portions, provide track grooves for the stencils entering and leaving station 118 while .the transfer frame is in its upper position. Resiliently mounted rollers 132, 134 on the adjacent fixed portions of upper track 82 engage upper portions of the upwardly moving transfer carriage and maintain these portions in proper positions at transfer station 110. In its lower position, the tissue portion of a carried stencil is in positions to be struck by the typewriter type characters with advances and line spacings in accordance with conventional typewriting procedures.

A feature is that the stencil transfer operation may not be accomplished until the typewriter carriage is in the carriage-return position of Fig. l. A normally open electric switch 136 is mounted on a fixed supporting part of the apparatus and is closed only when its roller arm 137 is engaged by an abutment 138 on the carriage 20. At other times, switch 136 is open in the electrical control circuit and depression of key S cannot energize the circuit.

The mentioned successive and rapid movements of a stencil at station 110, in response to depression of key S, is effectively accomplished as the result of the action of solenoid-controlled ratchet devices on the power-take-off shaft 62 which is below table 12 and which rotates whenever manual switch 140 (Fig. 11) is closed to energize motor 68. However, the sprockets 60 and 70 on the shaft 62 are loose on the shaft as shown in Fig. 10 and do not rotate until carried around by the associated pawls, indicated at 142 and 144 respectively, which are arranged and adapted for coaction with ratchet wheels 146 and 148, respectively, which are fixed on shaft 62 for rotation therewith. Pawl 142 is biased toward engagement with ratchet wheel 146 by spring 150, and pawl 144 is biased toward engagement with ratchet wheel 148 by spring 152. v

Pawl 142 normally is held out of engagement with ratchet wheel 146 by the adjacent end of a bar 154 which is slidably supported in bearing positions 156, 158 of a bracket 160 on shelf 66. The other end of bar 154 is connected by link 162 to the armature 164 of a solenoid 166 which is suitably supported on shelf 66. The other pawl 144 is similarly held out of engagement with ratchet wheel 148 by the adjacent end of a bar 168 which is slidable in bearing portions 170, 172 of bracket 174, and which has its other end connected by link 176 to the armature 178 of a solenoid 180.

Assuming that motor 68 is operating in response to closing of manual switch 140, the power-take-ofi shaft 62 and ratchet wheels 146,148 will be rotating clockwise as viewed in Fig. 1, but sprockets 60 and 70 will remain stationary due to disengagement of pawls 142, 144. When key S is depressed, with carriage 20 in return position closing safety switch 136, the solenoid 166 is momentarily energized and draws bar 154 toward it, releasing pawl 142 into engagement with ratchet wheel 146. Sprocket 60 then rotates with ratchet wheel 146 but only through one complete revolution because bar 154 is moved back to its original position, by spring 182, following the momentary energization of solenoid 166. Hence, as sprocket 60 completes a revolution, pawl 142 is again disengaged by bar 154. During this single revolution of sprocket 68, the shaft 50 is driven which, through bevel gears 54 drives shaft 46. Rotation of shaft 46 actuates connecting rod 40 to effect rocking movements of gear segment 32 and rotations of platen roll shaft 24, through pinion gear 28.

The initial portion of a said complete rotation of sprocket 60 rocks gear segment 32 counter-clockwise, as viewed in Fig. 4, which rotates shaft 24 and the platen roll 22 clockwise. The transfer frame 116 is thereby elevated to carry a stencil therein back into its vacated position in the tracks 82, 84, at station 110, at which time the lost motion pin-in-slot connection in the linkage to gear segment 32 leaves frame 116 momentarily stationary. Precisely at this time the solenoid 180 becomes energized through the medium of cam 184 on shaft 46, which closes a switch 186 in the circuit to solenoid 180. Bar 168 is drawn toward solenoid 180 to release pawl 144 whose engagement with ratchet wheel 148 effects rotation of sprocket 70. This rotation of sprocket 70 also is limited to a single revolution inasmuch as bar 168 is pulled by spring 188 back to its original position following the momentary energization of solenoid 180.

However, the rotation of sprocket 70 effects rotation of cam 80 and stencil-pushing movement of lever 94 and pusher 92. Transfer frame 116 remains stationary at station 110 only long enough to permit an advancing stencil to move into the frame at which time the linkage to gear segment 32 picks up the segment and rotates it clockwise (Fig. 4). The platen roll and its shaft are thereby rotated counter-clockwise to move the transfer frame and the stencil therein down to the platen roll. The stencil pusher 92 meanwhile will move back to its original position, as shown in Fig. 1.

The described cycle of operations is extremely rapid, as compared with the prior disagreeable and timeconsuming procedures involving manual insertion and removal of individual stencils to and from a typewriter.

The stencils are of a conventional variety having a frame within which a tissue portion is mounted. The tissue portion, on which type characters are to be formed by the type characters of the typewriter, has a film or coating thereou'and this film or coating preferably is moistened to condition it for effectively receiving an impression when struck by a type character of the typewriter. The invention includes efiicient means for suitably moistening stencils in the tracks 82, 84 and for effectively blotting each moistened stencil to remove excess water and moisture before it reaches the transfer station 110.

A frame indicated generally at 190 is suitably mounted on the tracks 82, 84, it being represented as having supporting brackets 194, 194 secured to the lower track 84. Two generally similar frame sections are hinged to the brackets 194, 194, extending upwardly on opposite sides of the tracks and resiliently biased toward each other by a spring 196 which is removably secured at its opposite ends to projections 198, 200 on the upper margins of the two frame sections. As shown, the frame 190 extends over two stencil-moistening stations 202, 204 and over one stencil blotting station 206. A wick 208 is mounted on each frame section at each moistening station .202, 204, each being wrapped over suitable backing material to provide the substantial bulges for engaging sides of a stencil tissue as best seen in Fig. 4, and each extending down into a water container 210 which may be supported on the brackets 194. Hence, assuming that water is within container 210, all of the wick parts opposite stencil tissues will be maintained wet or moist as a result of capillary action, and each stencil engaged between the wicks at each station 202, 204 will become effectively moistened. At the blotting station 206, each frame section carries absorbent material 212 formed into a bulge for engaging the stencil tissues and effectively removing excess moisture, as in Fig. 1. Spring 196 constantly biases the wicks and the blotters toward stencil engagement.

However, when stencils are to be advanced along the tracks 82, 84, the wicks and blotters automatically spread away from the stencils leaving the stencils free to be pushed along the tracks. The stencil pusher 92 has a portion 214 extending a substantial distance along the upper track 82, to the left as seen in Fig. 1. Portion 214 extends to each side of the track and has a cam surface 216 at the front side and a'cam surface 218 at the rear side. Each frame section of frame 190 has a roller 220 mounted thereon at an upper edge portion thereof for coaction with the cam surfaces 216, 218. Hence, the initial movement of the pusher 92, to the left in Fig. 1, causes the cam surfaces 216, 218 to engage the rollers 220 for spreading the frame sections and freeing the stencils for advancing along the tracks. The

frame sections remain spread throughout each complete cycle of movement of pusher 92.

Fig. 12 illustrates a known means for accomplishing stacking of the delivering stencils in the receiving container 108, at the left hand end of the apparatus. The rear Walls of the track grooves, opposite container 108, are cut away, and the inner surfaces of the front walls of the track grooveshave rounded protuberances 82 84 thereon which cause the foremost stencil in container 108 to be tilted a little as shown in Fig. 12, so that an advancing stencil moves in front of the tilted foremost stencil. As the advancing stencil engages and ridesover the protuberances 82, 84*, it forces the stack of stencils rearwardly and takes its place as the foremost stencil of the stack in container 108.

Fig. 13 illustrates a simplified mechanism for accomplishing direct drive of the stencil advancing mechanism from the shaft which effects actuations of the platen roll shaft 24. A shaft 46 is mounted in suitable bearings 48', 48. The connecting rod 40 is connected at 42 to the arm 44 which is fixed on one end of shaft 46, and a bevel gear 54 is fixed on the other end of shaft 46'. The cam 80, which eifects advances of the stencils, is

fixed on a shaft 76' which is mounted in suitable bearings 78 and has a bevel gear 54" fixed on its forward end, in mesh with bevel gear 54. One element 222 of a clutch is fixed to shaft 7 6' and has a plurality of radial teeth 224 thereon. A sprocket 74' is fixed on a sleeve 226 which is loose on shaft 76, a hub portion 228 of the sprocket serving as the second'element of the clutch, with radial grooves 230 therein for receiving the teeth 224 of element 222. A relatively heavy coil spring 232 is under compression between the sprocket and an abutment means 234 on sleeve 226, constantly biasing element 228 into driving engagement with element 222.

Sprocket 74' has chain drive connection at 72 with a single sprocket 70' on shaft 62 which is below table 12 on shelf 66. Only one ratchet wheel 146 and one .pawl 142 are required on shaft 62, and only one of the pawlcontrolling bars 154 is requisite in the Fig. 13 embodiment. Depression of typewriter key S energizes the armature 166 as previously described, assuming that switch 136 is closed. Pawl 142 is mounted on shaft 62 and, when released, engages ratchet wheel 146 which is fixed on motor-driven sleeve 63. The pawl 142 and shaft 62', and sprocket 70' on shaft 62', make one complete rotation for effecting one complete rotation of each of the shafts 76 and 46.

Cam 80 on shaft 76' is designed and arranged to effect a stencil advance only at the precise time when transfer carriage 116 is at rest at its upper limit of travel, in position to receive an advancing stencil.

It will-be obvious that various changes may be made in the disclosed embodiment of the invention within the scope of the appended claims, and it is intended that the patent shall cover, by suitable expression in the appended claims, whatever features of patentable novelty exist in the invention disclosed.

I claim as my invention:

1. Stencil-character-forming apparatus, comprising a typewriter having a platen roll and type characters keyactuatable selectively into coacting relation to the platen roll, track means along which stencils in end to end succession are movable between an inlet station at which stencils from a supply enter said track means in intermittent succession, and an outlet station at which stencils leave said track means in intermittent succession, said track means having a transfer station between said inlet and outlet stations, stencil-advancing mechanism operable intermittently for advancing said succession of stencils one stencil length along said track means, and stencil transfer means at said transfer station mounted for move ment generally transversely of the direction of advance of stencils along said track means, said stencil transfer means being arranged and adapted to receive therein each stencil of the succession as it is advanced to said transfer station, and means operative following each stencil advancing operation of said stencil advancing mechanism for moving the stencil in said transfer means away from said track means to said platen roll and into position to be struck by said key-actuated type characters.

2. Stencil-character-forming apparatus as defined in claim 1 wherein said stencil. advancing mechanism and said stencil transfer means are electrically operated, and there is manually actuatable control means at said typewriter for effecting at will a cycle of electrical operations of said stencil transfer means and said stencil advancing mechanism, a said cycle consisting of a movement of a stencil in said transfer means from said platen roll to said track means, followed by an advance of stencils along said track means, and then a movement of the stencil newly advanced into said transfer means from said track means to said platen roll.

3. 'Stencil-character-forming apparatus as defined in claim 1 wherein the individual stencils of said succession of stencils move intermittently and in succession to and through a stencil moistening station prior to reaching said transfer station, stencil moistening means at said moistening station for engaging each stencil in succession while it is at rest at said moistening station, and means responsive to each operation of said stencil-advancing mechanism for separating said stencil-moistening means from the stencil at said moistening station thereby to free the latter said stencil for advance along said track means.

4. Stencil-character-forming apparatus comprising a typewriter having a platen roll and key-actuatable type characters, track means above said typewriter along which stencils in end to end succession are movable to a transfer station, means for pushing the stencils one stencil length along said track means thereby to advance said stencils in succession to said transfer station, a transfer carriage on said typewriter and movable between said transfer station and said platen roll, stencil-receiving and holding means on said carriage, means for effecting a stencil-pushing operation of said pushing means while said transfer carriage is at said transfer station thereby to advance a stencil into said receiving and holding means of the carriage, and mechanism operative following each said operation of said pushing means for moving the carriage and the stencil therein from said transfer station to said platen roll in direction generally transversely of the direction of advance of stencils along said track means.

5. Stencil-character-forming apparatus as defined in claim 4 wherein said means for effecting a stencil-pushing operation of said pushing means comprises a normally open switch in an electrical circuit mounted and adapted to be closed by depression of a particular key of said typewriter, a driven shaft, a ratchet wheel fixed on said driven shaft and rotating therewith, means loose on said driven shaft, and having drive connection to said stencilpushing means, a pawl carried by said loose means and yieldingly biased toward engagement with said ratchet wheel whereby said loose means on the shaft rotates with said ratchet Wheel when said pawl is in engagement with the ratchet wheel, and means responsive to closing of said switch for releasing said pawl into engagement with said ratchet wheel and for disengaging the pawl approximately at the end of a complete rotation of said loose means.

6. Stencil-character-forming apparatus as defined in claim 4 wherein there is a driven shaft having first and second ratchet wheels fixed thereon and first and second means loose on said shaft with drive connections respec' tively to said transfer carriage and to said stencil-pushing means, a first pawl carried by said first loose means on the shaft and yieldingly biased toward engagement with said first ratchet wheel, a second pawl carried by said second loose means on the shaft yieldingly biased toward engagement with said second ratchet wheel, means responsive-to depression of a particular typewriter key for releasing said first pawl into engagement with said first ratchet wheel and for disengaging said first pawl approximately at the end of a complete rotation of said first loose means onsaid driven shaft, said drive connection of said first loose means effecting movement of said transfer carriage from said platen roll to said transfer station and back to said platen roll in response to said approximate complete rotation thereof and there being lost motion in said drive connection whereby the carriage stands stationary for a predetermined period at said transfer station, and means responsive to rotation of said first loose means for releasing said second pawl into engagement with said second ratchet wheel for effecting a said operation of said stencil-pushing means while said carriage is stationary at said transfer station, and for disengaging said second pawl approximately at the end of a complete rotation of said second loose means on said driven shaft.

7. In a stencil-character-forming apparatus having a shaft with aplaten roll fixed thereon, a stencil carriage for holding a stencil therein in a predetermined relationship to said platen roll, guide means for holding a plurality of stencils in end to end succession, stencil advancv ing mechanism operable for intermittently advancing said stencils one stencil length along said guide means, a drive connection between said carriage and said platen roll shaft whereby the carriage is moved toward said guide means in response to rotation of said shaft in one direction and away from said guide means and toward said platen roll in response to rotation of said shaft in the opposite direction, and mechanism for effecting intermittent successive rotations of said shaft in opposite directions and for effecting an operation of said stencil advancing mechanism in the interim between the said opposite rotations of said shaft, whereby said carriage carries a stencil between said platen roll and said guide means, receives therein an incoming stencil advanced along said guide means, which incoming stencil pushes the previous stencil out of the carriage, and carries the newly received stencil away from said guide means and into said predetermined relationship to said platen roll.

8. In a stencil-character-forrning apparatus having a typewriter with a movable typewriter carriage on which a platen roll and platen roll shaft are mounted, the combination therewith of guide tracks fixed in positions above said carriage, means for intermittently advancing stenoils in succession along said tracks to a transfer station,

a transfer carriage movably mounted on said typewriter.

carriage, a drive connection between said platen roll shaft and said transfer carriage whereby the latter said carriage moves in response to rotations of said shaft, guide means on said typewriter carriage for guiding said transfer carriage on a course leading between said platen roll and said guide tracks at said transfer station, and means on said transfer carriage for receiving and holding a stencil advanced along said tracks to said transfer station, whereby said received stencil moves with said transfer carriage in response to rotations of said platen roll shaft.

9. In a stencil-character-forming apparatus having atypewriter with a movable typewriter carriage on which a platen roll and platen roll shaft are mounted, the combination therewith of means for guiding stencils in succession to a transfer station above and generally opposite said platenroll, a transfer carriage movably mounted on the typewriter carriage for movements between said transfer station and said platen roll, means for moving said transfer carriage generally upward into said transfer station in response to rotation of said platen roll shaft in one direction, and for moving said transfer carriage generally downward to said platen roll in response to rotation of said platen roll shaft in the opposite direction, and mechanism operative only when said transfer carriage is at said transfer station for advancing stencils along said guiding means thereby to advance a stencil into said transfer carriage prior to each said generally downward movement of the transfer carriage.

l0. Stencil-character-forming apparatus comprising track means for guiding stencils in succession to a transfer station, mechanism, including a platen roll, arranged below said track means, a transfer carriage having stencil receiving means thereon and movable between said transfer station and said platen roll, means for effecting a movement of said carriage from said platen roll to said transfer station in response to rotation of said platen roll in one direction and for effecting a movement of said carriage from said transfer station to said platen roll in response to rotation of said platen roll in the opposite direction, and mechanism operative only when said carriage is at said transfer station for advancing a stencil from said track means into said receiving means on said carriage.

11. Stencil-character-forming apparatus comprising an electric typewriter having a movable carriage on which a platen roll is rotatably mounted, a transfer carriage movably mounted on said typewriter carriage, a drive connection between said platen roll and said transfer carriage whereby said transfer carriage moves in one direction in response to rotation of said platen roll in one direction and moves in the opposite direction in response to rotation of said platen roll in the other direction, track means above the typewriter for guiding stencils in succession to a transfer station generally opposite said platen roll, electrically responsive means for effecting predetermined rotational movements of said platen roll, first in one direction and then in the other direction thereby to effect movements of said transfer carriage from said platen roll to said transfer station and then back to said platen roll, and mechanism operative only when said transfer carriage is at said transfer station for advancing a stencil from said track means into said transfer carriage.

No references cited. 

